I'm very sorry for any inconvenience this may have caused you. Unfortunately, this sounds like it may need servicing. And from what I can tell, this model is for the UK. (Correct me if I'm wrong.) Since I support US products and customers, here's the Samsung UK portal for support on that product: http://www.samsung.com/uk/support/model/UE46D6510WKXXU
Got home last night to find Samsung UE46D6510 did have sound but no picture and displayed just a black screen. When turning on there is a white glow towards the top right of the screen and it then goes black. It does not display Samsung Smart logo when turned on. We have had the tv for 18 months and this is the second picture problem in the last 6 months, the first being the appearance of 2 black horizontal lines along the top of the screen. Samsung were very unhelpful on the first occasion but thankfully these lines disappeared after a few weeks. With regards to the new problem I will contact them tomorrow as today is Sunday. Has anyone else experienced this problem? Is it fixable? Were Samsung supportive? I have read a lot about capacitor problems with Samsung Smart tv's and it would appear there are some serious issues with them which Samsung seem keen to keep quiet. My tv is now unplugged and will be for 24 hours as someone else reported that this worked. We left it off overnight but no joy.
Any help, support or advice would be greatly appreciated. I will be blogging my experience with Samsung support so stay tuned.